Some factors and drugs are known to have a hepatocyte regenerating action. For example, Archive of Pathology, 16, 226-231 (1993) teaches that when a diet containing 1 wt % of a dried thyroid gland powder was continuously fed after partial hepatectomy, the liver weight increased significantly over the control from the seventh day of the partial hepatectomy.
Journal of Biological Chemistry, 247, 1757-1766 (1972) reports that a liquid mixture of triiodothyronine (T3), mixed amino acids in solution, glucagon and heparin caused DNA synthesis in the liver.
In addition, a growth factor for the primary culture of hepatocytes in mature rats was purified from rat sera 24 hours after 70% partial hepatectomy and designated HGF (hepatocyte growth factor) or hepatotropin, as described in Biochemical and Biophysical Research Communications, 122, 1450-1459 (1984).
Insulin and glucagon are also important factors to liver regeneration, as described in Advances in Enzyme Regulation, 13, 281-293 (1975), and in Japan, ever since Okita et al. reported the application of an insulin-glucagon therapy to fulminating hepatitis in Gastroenterologia Japan., 14, 453 (1979), they have been commonly used in clinical cases.
Valine, isoleucine and leucine, which are branched-chain amino acids, have been reported to be capable of ameliorating hepatic encephalopathy and septic encephalopathy or saving proteins during invasion, and Hepatoamine (registered trademark), Hepan (registered trademark), Aminoleban (registered trademark), Amiparen (registered trademark), Amizet (registered trademark) and Aminic (registered trademark) are commercially available as amino acids in solution. However, it is entirely unknown that valine has a hepatocyte regenerating action.
In recent years, hepatocyte growth factor (HGF) was purified from rats and humans, followed by successful cloning of cDNA, and in view of its capability for proliferating primary cultured hepatocytes, as well as the results of increased blood HGF activity in hepatopathy and induced expression of HGF mRNA, clinical application of the HGF is expected to materialize in the future but, as of today, this has not been commercialized.
The only treatment that is presently held in Japan to have a liver regenerating effect is glucagon-insulin therapy (GI therapy). However, the effectiveness of this GI therapy has not yet been recognized in Europe and the United States of America.